Wheat and casein dog chew with modifiable texture

ABSTRACT

A completely digestible highly nutritious dog chew formulated primarily of wheat flour, casein and starch carbohydrate, the texture of hardness of which is easily modified to suit a particular dog by the dog owner. By irradiating the chew in a microwave oven, the chew is caused to expand and is thereby rendered more easily chewable.

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/993,748 filed Dec. 19, 1997, which is a continuation-in-partof U.S. patent application Ser. No. 08/738,423, filed Oct. 25, 1996 nowU.S. Pat. No. 5,827,565.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to dog chews and more particularlypertains to heat-modifiable edible dog chews.

2. Brief Description of the Prior Art

Most dogs enjoy chewing on things although preferences vary as to thehardness of the substances favored. Some dogs like to chew on very hardmaterials such as cow bones, wood, nylon or polyurethane, others prefersofter chews such as rawhide, while still others favor freeze driedsnacks. Some dogs, due to their age, may not be able to chew on the veryhard substances. Young dogs have insufficiently developed teeth, whileold dogs may have diseased gums or may have lost some of their teeth.

Many indigestible objects are given to dogs as a chew and although thedogs may enjoy chewing thereon, the objects are often swallowed in wholeor in part. Once swallowed, these objects or fragments thereof can havean adverse effect on the dogs digestion and can become impacted in thedog's intestinal tract with life-threatening consequences. By way ofexample, dog chews have been marketed which utilize an ethylenecopolymer which can be fractured by the chewing action of a dog, andwhen ingested can block the dog's stomach passages.

In an attempt to make certain edible chews more appealing to dogs, awide variety of additives are incorporated in products that, apart frombeing low in nutritional value, do not comprise particularly healthysupplements to a dog's diet. Often times the chew's taste is enhanced inorder to make the particular chew more appealing to dogs who areotherwise not drawn to its hardness or texture.

Other edible dog chews have been marketed which have a comparativelyshort shelf life and therefore must be replaced by retail outlets atfrequent intervals. Yet other prior art dog chews are lacking instructural integrity whereby they are susceptible to breakage duringhandling and shipping.

SUMMARY OF THE INVENTION

The present invention provides a dog chew that is completely digestible,highly nutritious, devoid of deleterious additives and is of amodifiable texture or hardness quickly and easily tailorable by theowner to suit the need or preference of his particular dog. The chewincludes ingredients, which are molded into preselected shapes and maybe packaged in moisture-proof packaging to maintain a preselectedmoisture content during storage and handling. Upon removal from thepackage, the chew can be caused to swell up four to eight times itsoriginal volume, if desired, by subjecting it to microwave radiation.With this procedure, the chew's texture or hardness can be adjusted fromits original high density, extremely hard state, to a low density,expanded, easily chewed state depending on the amount of microwaveexposure. The chew can thereby quickly and easily be tailored to thetexture preference of a wide variety of dogs, from a strong, large,healthy dog to a small puppy with puppy teeth or an older dog withdecayed molars. In addition, dog chews embodying the present inventioncan provide a long shelf life, e.g., three to six years or more.

More particularly, a formulation according to the present inventioncomprises the intermixing of about 40% by weight wheat flour, about 55%by weight casein, about 5% by weight starch carbohydrate (humectant),and optionally with 1 to 5% gelatin by weight. Additionally, a verysmall amount of flavoring and coloring can be added to enhance taste andappearance. The mixture is subsequently melted by heat and pressure andmolded into preselected shapes. The temperatures, moisture levels andhandling during the mixing and molding and subsequent packagingprocedure are precisely controlled to ensure that the resulting producthas a moisture content of between 10-14%, and preferably at least 12%.The resulting chew is hard while an approximate one half to three minuteexposure within a standard household microwave oven results in a light,easily chewed product for the dog.

Other features and advantages of the present invention will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, which illustrate by way of example, theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the preferred embodiment of the invention in itsunexpanded state;

FIG. 2 illustrates the preferred embodiment of the invention in itspartially expanded state; and

FIG. 3 illustrates the preferred embodiment of the invention in itsfully expanded state.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention provides a highly nutritious, completelydigestible dog chew. The dog owner can quickly and easily modify thetexture or hardness of the chew to suit his particular dog by simplymicrowaving the chew for a short period of time.

The ingredients initially combined to form the chew of the presentinvention include a mixture of water, about 40% by weight wheat flour,about 55% casein, about 5% by weight starch carbohydrate (humectant) andoptionally, about 1 to 5% gelatin by weight. The wheat flour should beof a fine consistency and may be made from USA red winter wheat for goodresults. The starch may be of vegetable origin, e.g., potatoes, corn ora mixture thereof. Casein which is a protein derived from milk is highlynutritious and easily digested by dogs. The gelatin content affects thehardness of the product, i.e., the higher the gelatin content, thesofter the product.

In order to cause the components of the above-described ingredients tobe intimately combined with one another, the mixture is heated to thecomponents' melting temperatures of about 250° F. to 400° F. under1,000-25,000 PSI pressure. Adjustment of the mixture's moisture contentto about 20-30% is accomplished by either heating to drive off excessmoisture, or steam injection, to increase moisture at which point thematerial is either extruded, or preferably, molded into preselectedshapes. A standard injection moldings machine is the preferred method ofproducing the chews of the present invention. A bone shape for the chew,such as illustrated in FIG. 1 is preferred so that the public morereadily recognizes the intended use of the product.

The molded product is dried to about 10-14% moisture content.Thereafter, the molded product is preferably packaged in moisture-proofpackaging to preserve the moisture content of the chew at between the10-14% magnitude. Higher or lower moisture content can affect theshelf-life of the product. Too much moisture causes the chew todeteriorate without the addition of stabilizers. Less than the 10-14%moisture level can render the product hygroscopic.

Upon removal for the package, the person feeding the dog can modify thetexture or hardness of the chew by heating in a microwave oven. Theexpansion of the moisture within the chew causes the chew to expand.Subjecting the chew to microwave radiation facilitates the heating ofareas deep within the chew at the same time the exterior heats up andexpands. FIG. 1 illustrates the chew 10 prior to heating, in whichstate, it has a substantially smooth exterior surface 12 and is of anextremely hard texture preferred by some dogs. A short exposure tomicrowave radiation initiates the expansion process. FIG. 2, illustratesthe chew 10 in a partially expanded state evidenced by a partiallybubbled surface 14. In this state, the chew 10 is of an intermediatehardness preferred by some dogs. FIG. 3, illustrates the chew 10 infully expanded state as may result from a 30 to 180 second exposure in astandard household microwave oven. The entire chew 10 has a bubbledsurface 14 and is easily chewable by most dogs. The chew in this state,is ideal for small dogs with puppy teeth or old dogs who suffer from gumdisease or who may have lost teeth. Sufficient exposure to microwaveradiation will cause the chew to expand four to eight times its originalvolume, with a commensurate reduction in hardness. In a preferred methodof making the dog chew of the present invention, about 40 pounds ofwheat flour, about 55 pounds of rennet casein, about 5 pounds of starchcarbohydrate (humectant) and about 2 pounds of gelatin are screened toabout 30 mesh and are then intermixed in a conventional injectionmolding machine hopper blender. Attractants, such as beef or hamflavoring, as well as colorings, can be added in very small quantitiese.g., 1.5% to enhance the appeal of the product to both the dog as wellas the buyer. Vitamins can also be added. A feeding screw transports theintermixed material to an injection molding machine. The stressesimposed by the mechanical action on the material substantially raisesits temperature while steam injection can be employed to ensure that asufficiently high temperature is attained wherein the mixture melts andis moldable. Depending on the type of injection molding machine utilizedand the characteristics of the specific casein and gelatin, moldingtemperatures can vary from about 250° F. to 400° F. and under1,000-25,000 PSI of pressure. The molded chew is dried to about 10-14%moisture and then preferably packaged in a moisture proof packing toensure that no moisture is lost.

In use, the chew is given to the dog in its initial and hardest state.If the dog is unwilling or unable to chew on it, the chew is microwavedfor short time increments and re-offered to the dog until the chewreaches a state of expansion and a degree of hardness preferred by thedog. Large, strong and healthy dogs would probably prefer the chew inits unmodified and hardest state while very small, young or very olddogs would prefer the chew in its most expanded state.

It should be particularly noted that an edible dog chew made inaccordance with the present invention does not dry out and fall apartafter being packaged and accordingly can have a shelf life of severalyears even without being packaged in a waterproof container.Additionally, the dog chew is extremely resistant to breakage duringshipping and handling.

While a particular form of the invention has been illustrated anddescribed, it will also be apparent to those skilled in the art thatvarious modifications can be made without departing from the spirit andscope of the invention. Accordingly, it is not intended that theinvention be limited except by the appended claims.

What is claimed is:
 1. A method of producing a hardness-adjustableedible dog chew, consisting essentially of the steps of forming amixture consisting essentially of wheat flour, casein, water and astarch carbohydrate as a humectant, and adjusting the water content ofsaid mixture to about 20-30 wt. %; andinjection molding such mixtureinto the shape of the dog chew, wherein said water content, subsequentto injection molding, is reduced below said 20-30 wt. %, and packagingsail dog chew wherein the hardness of said chew can be adjusted bymicrowave heating.
 2. The method of claim 1 wherein said starch isderived from potatoes, corn or a mixture thereof.
 3. The method of claim1 wherein said starch is present at about 5% by weight.
 4. The method ofclaim 1 wherein said wheat flour is present at about 40% by weight. 5.The method of claim 1 wherein said casein is present at about 55% byweight.
 6. The method of claim 1 wherein the moisture content subsequentto injection molding is adjusted to about 10-14% by weight.
 7. Themethod of claim 6, wherein the moisture content subsequent to injectionmolding is about 12% by weight.
 8. The method of claim 1 wherein saidwheat flour is USA red winter wheat.
 9. The method of claim 1 whereinsaid casein is derived from milk.
 10. The method of claim 1 wherein saidmixture also contains an attractant.
 11. The method of claim 10 whereinsaid attractant is present at about 1-5% by weight.
 12. The method ofclaim 10 wherein said attractant is selected from the group consistingof a beef flavoring, a ham flavoring, or mixtures thereof.
 13. Themethod of claim 1 wherein said mixture is injection molded at a pressureof about 1000-2500 psi and at a temperature of about 250-400° F.